When handling blood or biological fluids, medical laboratory personnel or technicians are constantly threatened with exposure to toxic or life-threatening particles. This danger is especially high when these fluids are preserved in vacuum tubes, as is usually the case with blood samples. When opening vacuum tubes, the technician must exercise extreme caution since the sudden onrush of air into the vacuum displaces infinitesimal amounts of fluid thereby propelling invisible fluid particles into the air. The subsequent inhalation or ingestion of these particles or aerosols places the technician in peril of contracting contagious diseases such as hepatitis and AIDS.
Various apparatus have been used to reduce the risk of exposure, such as surgical masks. Such masks, however, have proved to be costly and inadequate since they are uncomfortable to wear and require placement by the technician. Vacuum hoods are similarly undesirable since their size and weight render them unmovable. A technician must therefore interrupt his work in one area of the laboratory to seek the nearest vacuum hood before opening a container or handling toxic or life-threatening materials. These hoods are also expensive to purchase and costly to operate.
Several eye and face guards have been developed primarily for use with routers, drills and other such machinery. Typical examples of such guards can be found in U.S. Pat. Nos. 1,217,838 (eye shield for lathes and grinding wheels); 2,399,707 (face guard for routers); 2,825,268 (eye and body shield for metal cutting machines); 3,183,629 (splash curtain for belt grinder); and 4,423,568 (splash guard for glass router). These guards are typically designed to protect the machine operator from flying metal particles and are usually equipped with means for attaching the apparatus to the machine.
U.S. Pat. No. 3,127,855 relates to a laboratory apparatus shield which has two finger holes at its uppermost edge for transporting the shield. The existence of the holes renders this shield ineffective for the method disclosed herein because aerosols may easily escape through these holes to endanger the technician.
None of these guards or shields is capable, however, of preventing inhalation and ingestion of airborne aerosol particles of toxic or life-threatening materials by medical laboratory personnel.